The construction of core-shell structure can effectively reduce the quenching effect on the surface of material and regulate ion-ion interaction, which has become one of the effective ways to enhance and regulate the spectral characteristics of rare-earth upconversion luminescent materials. In this paper, a variety of NaYbF ₄: 2%Er ³⁺micron core-shell structures are constructed with the help of epitaxial growth technology, effectively improving the red up-conversion emission of Er ³⁺ions. The prepared microcrystals with core-shell structures are of hexagonal phase microdisks, and their sizes are relatively uniform. In order to better obtain the material spectral data, a confocal microscopic spectroscopy is used to study spectral properties. Under 980 nm near-infrared laser excitation, the red emission intensity of single NaYbF ₄:2%Er ³⁺@NaYbF ₄@NaYF ₄core-shell-shell microdisk is 4.6 times higher than that of NaYbF ₄:2%Er ³⁺micron disk, and the red-to-green ratio increases from 6.3 to 8.1. Meanwhile, Ho ³⁺ions are introduced into the NaYbF ₄:2%Er ³⁺@NaYbF ₄: 2%Ho ³⁺@NaYF ₄core-shell-shell microdisk, and the red emission intensity is nearly 6.7 times higher than that of single NaYbF ₄: 2%Er ³⁺microdisk, and the red-to-green ratio increases from 6.3 to 9.4 through the interaction between ions. The microcrystal spectral characteristics and luminescence kinetics of different core-shell structures are studied, showing that the red emission enhancement of Er ³⁺ions is mainly derived from the construction of different core-shell structures, which can effectively enhance the cross-relaxation between Er ³⁺ions, the energy back transfer between Yb ³⁺and Er ³⁺ions, and the energy transfer from Ho ³⁺ions to Er ³⁺ions. The micron core-shell structures with efficient red emission in this study has great application prospects in the fields of luminescence, anti-counterfeiting and optoelectronic devices.